The subject invention is directed to the art of paper sheet handling and, more particularly, to a clutch driven inverter shaft for use in a sheet inverter system.
The invention is especially suited for use in the paper handling and inverter system of an electrophotographic printing machine and will be described with reference thereto; however, as will become apparent, the invention could be used in many types of paper sheet handling systems in a variety of different machines.
In electrophotographic printing machines, it is sometimes necessary or desirable to flip or reverse the orientation of a moving paper sheet in a duplex processing operation to provide two-sided copying or for other reasons known to those skilled in the art. Such orientation changing is generally referred to as sheet "reversing" and has been accomplished in many different ways.
One prior art method of reversing has been to receive a first end of a moving sheet through a continuously moving roll nip and into an inverter against a reversing spring positioned between two opposing wire guides. The trailing or free end of the sheet is entirely pushed into the inverter by the nip only to be immediately expelled therefrom through an exit passage in the inverter. During this process, the sheet itself must entirely exit the nip and change direction abruptly. This leads to reliability problems especially for skewed sheet inputs and sheets having different weights, dimensions and textures. Also, the sheet edges are often damaged by engagement with the reversing spring during the inversion process.
It has been found desirable to develop a new and improved sheet inverter apparatus which overcomes the above noted problems and others encountered in the prior art. The present invention meets these needs and others and provides such an inverter which is simple, reliable fast and not likely to damage the documents handled therein.